We want to determine the acetylsalicyclic acid content of a series of aspirin tablets by titration with

Question:

We want to determine the acetylsalicyclic acid content of a series of aspirin tablets by titration with NaOH(aq). Each of the tablets is expected to contain about 0.32 g of HC₉H₇O₄. What molarity of NaOH(aq) should we use for titration volumes of about 23 mL? (This procedure ensures good precision and allows the titration of two samples with the contents of a 50 mL buret.)

HC₉H₇O₄(aq) + OH^-(aq) → C₉H₇O₄^-(aq) + H₂O(l)